how to fix P0171 code in BMW X3 G01 (2018-2024)

Solution

1. Preparation

• Gather tools and parts required.
• Disconnect the battery to prevent any electrical issues while working on the vehicle.
• Ensure the engine is cool before starting work on the intake system.

2. Inspect Air Intake System

• Sub-steps:

  • Visually inspect all vacuum hoses connected to the intake manifold for cracks or disconnections.
  • Check the intake manifold gasket for signs of leaks.
  • Use carburetor cleaner to spray around the intake area while the engine is running to detect vacuum leaks (watch for RPM changes).

• Tools Required:

  • Screwdriver set
  • Carburetor cleaner

3. Clean or Replace MAF Sensor

• Sub-steps:

  • Locate the MAF sensor on the air intake hose.
  • Remove the electrical connector and unscrew the sensor from the housing.
  • Clean the sensor using MAF cleaner spray (do not touch the sensor with fingers).
  • Reinstall the sensor and reconnect the electrical harness.

• Tools Required:

  • Torx or Philips screwdriver
  • MAF cleaner spray

4. Check and Replace Fuel Filter (if necessary)

• Sub-steps:

  • Locate the fuel filter in the fuel line.
  • Relieve fuel pressure by removing the fuel pump relay and starting the vehicle until it stalls.
  • Disconnect the fuel lines and remove the old fuel filter.
  • Install the new fuel filter, ensuring the flow direction is correct.

• Tools Required:

  • Fuel line disconnect tool
  • Wrench set

5. Test Fuel Injectors

• Sub-steps:

  • Disconnect the fuel injector harness from each injector.
  • Use a multimeter to check the resistance of each injector (consult specifications for correct values).
  • If an injector is faulty, remove it and replace it with a new injector.

• Tools Required:

  • Multimeter
  • Socket set